Learning techniques for cardiac arrhythmia detection

ABSTRACT

This document discusses, among other things, systems and methods to adjust arrhythmia detection using physiological information of a patient, including detecting a candidate cardiac event about a threshold, displaying the detected candidate cardiac event to a user, receiving user information about the detected candidate cardiac event, and adjusting an arrhythmia detection threshold based upon the received user information.

CLAIM OF PRIORITY

This application claims the benefit of priority under 35 U.S.C. § 119(e)of U.S. Provisional Patent Application Ser. No. 62/437,876, filed onDec. 22, 2016, which is herein incorporated by reference in itsentirety.

TECHNICAL FIELD

This document relates generally to medical devices, and moreparticularly, but not by way of limitation, to systems, devices, andmethods to detect cardiac arrhythmia.

BACKGROUND

Medical devices, such as Holter devices, Insertable Cardiac Monitors(ICM), Cardiac Event Monitors (CEM), Mobile Cardiac Telemetry (MCT), anddiagnostic patches can be used to monitor, detect, and in some cases,treat various cardiac conditions that can result in a reduced ability ofa heart to sufficiently deliver blood to a body. In some cases, heartconditions may lead to events of rapid, irregular, or inefficient heartcontractions, etc. These medical devices often use sophisticateddetection techniques for detecting and treating these events.

SUMMARY

This document discusses, among other things, systems and methods oflearning techniques for cardiac arrhythmia detection including adjustingcardiac arrhythmia detection using received user information ofcandidate cardiac events. The systems and methods disclosed herein canadjust arrhythmia detection by presenting candidate cardiac events to auser, receiving user information about the candidate cardiac events, andusing the received user information to adjust parameters, thresholds,and zones to detect cardiac arrhythmias events that the user wants tosee. In certain examples, the cardiac arrhythmia detection can beadjusted to identify cardiac arrhythmia events that may otherwise goundetected.

Example 1 is a system comprising: an input circuit configured to receivephysiological information of a patient; an arrhythmia circuit configuredto detect a candidate cardiac event about a threshold using the receivedphysiological information of the patient; and a user interfaceconfigured to display the candidate cardiac event to a user, and toreceive user information about whether the candidate cardiac eventshould be above or below the threshold, wherein the arrhythmia circuitis configured to adjust an arrhythmia detection threshold using thereceived user information that the candidate cardiac event should beabove or below the threshold.

In Example 2, the subject matter of Example 1 optionally includeswherein the arrhythmia circuit is configured to detect the candidatecardiac event using a detection parameter, and wherein the arrhythmiacircuit is configured to adjust at least one of the threshold or thedetection parameter using the received user information that thecandidate cardiac event should be above or below the threshold.

In Example 3, the subject matter of Example 2 optionally includeswherein the arrhythmia circuit is configured to detect a cardiacarrhythmia using the adjusted threshold or the adjusted detectionparameter.

In Example 4, the subject matter of any one or more of Examples 1-3optionally include wherein the arrhythmia circuit is configured toadjust the threshold within a predefined safety zone using the receiveduser information.

In Example 5, the subject matter of Example 4 optionally includeswherein the arrhythmia circuit is configured to detect a cardiacarrhythmia using the adjusted threshold.

In Example 6, the subject matter of any one or more of Examples 1-5optionally include wherein the arrhythmia circuit is configured todetect the candidate cardiac event within a target zone about thethreshold, and wherein the target zone includes a lower boundary belowthe threshold, and an upper boundary above the threshold.

In Example 7, the subject matter of any one or more of Examples 1-6optionally include wherein the received user information about whetherthe candidate cardiac event should be above or below the thresholdincludes positive received user information, neutral received userinformation, or negative received user information.

In Example 8, the subject matter of any one or more of Examples 2-7optionally include a counter, wherein the arrhythmia circuit isconfigured to adjust a count of the counter in response to the receiveduser information that the candidate cardiac event should be above orbelow the threshold, and wherein the arrhythmia circuit is configured toadjust at least one of the threshold or the detection parameter when thecount exceeds an update threshold.

In Example 9, the subject matter of any one or more of Examples 1-8optionally include wherein the arrhythmia circuit is configured toadjust a confidence parameter in response to the received userinformation that the candidate cardiac event should be above or belowthe threshold.

In Example 10, the subject matter of any one or more of Examples 6-9optionally include wherein the threshold is centered between the upperboundary and the lower boundary.

In Example 11, the subject matter of any one or more of Examples 6-10optionally include wherein the upper boundary is a predefined amountabove the threshold and the lower boundary is a predefined amount belowthe threshold.

In Example 12, the subject matter of any one or more of Examples 6-11optionally include wherein the upper boundary is a selectable amountabove the threshold and the lower boundary is a selectable amount belowthe threshold.

Example 13 is a method comprising: receiving physiological informationof a patient using an input circuit; detecting, using an arrhythmiacircuit, a candidate cardiac event about a threshold using thephysiological information of the patient; displaying, using a userinterface, the candidate cardiac event to a user; receiving, using theuser interface, user information about whether the candidate cardiacevent should be above or below the threshold; and adjusting, using thearrhythmia circuit, an arrhythmia detection threshold using the receiveduser information that the candidate cardiac event should be above orbelow the threshold.

In Example 14, the subject matter of Example 13 optionally includeswherein detecting the candidate cardiac event includes using a detectionparameter, and wherein adjusting the arrhythmia detection thresholdincludes adjusting at least one of the threshold or the detectionparameter using the received user information that the candidate cardiacevent should be above or below the threshold.

In Example 15, the subject matter of Example 14 optionally includesdetecting, using the arrhythmia circuit, a cardiac arrhythmia using theadjusted threshold or the adjusted detection parameter.

In Example 16, the subject matter of any one or more of Examples 13-15optionally include wherein adjusting the arrhythmia detection thresholdincludes adjusting the threshold within a predefined safety zone usingthe received user information that the candidate cardiac event should beabove or below the threshold.

In Example 17, the subject matter of any one or more of Examples 13-16optionally include detecting, using the arrhythmia circuit, thecandidate cardiac event within a target zone about the threshold,wherein the target zone includes a lower boundary below the threshold,and an upper boundary above the threshold.

In Example 18, the subject matter of any one or more of Examples 13-17optionally include wherein the received user information about whetherthe candidate cardiac event should be above or below the thresholdincludes positive received user information, neutral received userinformation, or negative received user information.

In Example 19, the subject matter of any one or more of Examples 14-18optionally include adjusting a count of a counter, using the arrhythmiacircuit, in response to the received user information that the candidatecardiac event should be above or below the threshold; and adjusting,using the arrhythmia circuit, at least one of the threshold or thedetection parameter when the count exceeds an update threshold.

In Example 20, the subject matter of any one or more of Examples 13-19optionally include adjusting a confidence parameter in response to thereceived user information that the candidate cardiac event should beabove or below the threshold using the arrhythmia circuit.

In Example 26, the subject matter of any one or more of Examples 1-35 toinclude “means for” performing any portion of any one or more of thefunctions or methods of Examples 1-25, or a “machine-readable medium”(e.g., non-transitory, etc.) including instructions that, when performedby a machine, cause the machine to perform any portion of any one ormore of the functions or methods of Examples 1-25.

This summary is intended to provide an overview of subject matter of thepresent patent application. It is not intended to provide an exclusiveor exhaustive explanation of the disclosure. The detailed description isincluded to provide further information about the present patentapplication. Other aspects of the disclosure will be apparent to personsskilled in the art upon reading and understanding the following detaileddescription and viewing the drawings that form a part thereof, each ofwhich are not to be taken in a limiting sense.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 illustrates an example system including an input circuit, anarrhythmia circuit, a user interface and a memory.

FIG. 2 illustrates an example method for detecting cardiac events fromphysiological information of a patient and adjusting the detection ofcardiac events based upon received user information.

FIG. 3 illustrates an example flow chart for adjusting arrhythmiadetection.

FIG. 4 illustrates an example graphical user interface for displaying acardiac event and receiving user information.

FIG. 5 illustrates an example graphical user response prompt forreceiving user information.

FIG. 6 illustrates an example cardiac event graph including heartinformation data, thresholds, safety zones, and target zones.

FIG. 7 illustrates a block diagram of an example machine upon which anyone or more of the techniques (e.g., methodologies) discussed herein mayperform.

DETAILED DESCRIPTION

Cardiac monitoring devices, such as Holter devices, Insertable CardiacMonitors (ICM), Cardiac Event Monitors (CEM), Mobile Cardiac Telemetry(MCT), and diagnostic patches, can be used to automatically detect anddiscriminate various cardiac events, including cardiac arrhythmias.Cardiac arrhythmias can include tachycardia, bradycardia, pauses, atrialarrhythmias, ventricular arrhythmias, or other cardiac arrhythmias.Cardiac monitoring devices can record information about one or morecardiac events, including a time of occurrence, a duration, an averageheart rate, an electrocardiogram, and other information related to thecardiac events. Monitoring devices and systems can be complex anddifficult to reprogram for clinicians and professionals. The number ofselectable parameters, thresholds, boundaries, and zones of cardiacmonitoring devices can be confusing and overwhelming to users, such asclinicians. Monitoring device data reports can also be overwhelming forclinicians, often including 50-200 pages of false positives that areunhelpful and burdensome.

The present inventors have recognized, among other things, that thecomplexity, confusion, and burden that existing cardiac monitoringdevices present to users, including clinicians, can be significantlyreduced using learning techniques for cardiac event monitoring. Incertain examples, parameters, thresholds, boundaries, or zones can beadjusted based on learning techniques and user information aboutcandidate cardiac events. Candidate cardiac events can be determinedfrom physiological information that falls within a zone about athreshold, and presented to a user to verify that the candidate cardiacevent is indeed a valid cardiac event. Learning techniques for cardiacevent monitoring, as described herein, can be used to improve operationor programming of a medical device including, coupled to, or configuredto receive physiological information of a patient from an input circuit.

Reduction or removal of the manual selection of parameters, thresholds,boundaries, and zones for cardiac monitoring devices can greatlysimplify the user experience. Presenting the user with a singlecandidate cardiac event at a time and requesting positive or negativeuser information about the single candidate cardiac event can reduce theburden that large data dumps place on the user. Adjusting the arrhythmiadetection using the received user information can lead to more accuratecardiac event detection tailored to both a specific patient's needs andthe clinician's preferences. Learning techniques for cardiac eventmonitoring, as described herein, can improve the accuracy of cardiacevent detection of a medical device including, coupled to, or configuredto receive physiological information of a patient from an input circuit.

In an example, initial arrhythmia detection can be based upon a trainingset of real-world data. This can include initializing parameters,thresholds, boundaries, and zones used for arrhythmia detection usingthe training set of real-world data. An input circuit can receivephysiological information of a patient (e.g., electrical or mechanicalinformation of the heart of the patient, respiratory information of thepatient, etc.). An arrhythmia circuit can be configured to detect acandidate cardiac event about a threshold using the physiologicalinformation. The user information about the candidate cardiac event caninclude whether the candidate cardiac event should be above or below thethreshold, whether the candidate cardiac event is a reportable event, orwhether the candidate cardiac event should be displayed to the user. Inan example, the threshold can be associated with a parameter used forarrhythmia detection. A user interface can be configured to display thecandidate cardiac event to a user and receive user information about thecandidate cardiac event. In an example, the received user informationconsists of positive received user information, neutral received userinformation, and negative received user information.

In an example, the arrhythmia circuit can be configured to increment acount of a counter for positive received user information in response topositive received user information. The arrhythmia circuit can beconfigured to adjust arrhythmia detection when the positive countexceeds a threshold. An arrhythmia circuit can be configured toincrement a count of a counter for negative received user information inresponse to negative received user information. The arrhythmia circuitcan be configured to adjust arrhythmia detection when a negative countexceeds a threshold.

In an example, the arrhythmia circuit can be configured to adjust aconfidence parameter in response to received user information. Theconfidence parameter can be decreased in response to negative receiveduser information and increased in response to positive received userinformation. The confidence parameter can be associated with anyparameter setting, threshold setting, boundary setting, or zone setting.Each parameter setting, threshold setting, boundary setting, or zonesetting can have their own associated confidence parameter. In anexample, the arrhythmia circuit can be configured to adjust arrhythmiadetection using the confidence parameter. Arrhythmia detection can beadjusted to present more candidate cardiac events based on a parameter,threshold, boundary, or zone with a higher associated confidenceparameter. In an example, adjusting the confidence parameter andarrhythmia detection using the confidence parameter can provide the userwith more accurate arrhythmia notification and avoid overloading theuser with false positive events. Adjusting arrhythmia detection caninclude adjusting an arrhythmia detection threshold.

In an example, the arrhythmia circuit can be configured to detect acandidate cardiac event within a target zone. The target zone can besituated about a threshold with a lower boundary below the threshold andan upper boundary above the threshold. Events that fall below thethreshold but within the target zone can be detected as candidatecardiac events. The arrhythmia circuit can be configured to presentthese candidate cardiac events, one at a time, to a user and receiveuser information about the candidate cardiac events, one at a time.

In an example, the arrhythmia circuit can be configured to present morecandidate cardiac events that fall below the threshold in response topositive received user information. The arrhythmia circuit can beconfigured to present fewer candidate cardiac events below the thresholdin response to negative received user information. The arrhythmiacircuit can be configured to present more or less of certain candidatecardiac events using a confidence parameter associated with thecandidate cardiac events.

In an example, the arrhythmia circuit can be configured to adjust thelower boundary of the target zone up in response to negative receiveduser information about the candidate cardiac events below the threshold.Detecting, displaying, receiving user information, and adjustingarrhythmia detection for candidate cardiac events within a zone, ratherthan just candidate cardiac events above a threshold, allows fordetection of candidate cardiac events that would otherwise goundetected. Adjusting the lower boundary of the target zone in responseto the received user information can increase the accuracy of arrhythmiadetection, resulting in the detection of more cardiac events the userwants to see, and less of cardiac events the user does not want to see.

In certain examples, the learning techniques can be applied to apopulation such that the received user information from every systemwithin the population adjusts the arrhythmia detection for all cardiacmonitoring system within the population. In certain examples, thepopulation is limited to a single clinic. In certain examples, thepopulation includes every device within a family of devices. In certainexamples, the population is a single system, or a single patient.

FIG. 1 illustrates an example system 100 including an arrhythmia circuit110, an input circuit 120, a user interface 130, a set of counters 140,a memory 150, an output circuit 160, and a database 170. The memory 150includes boundaries 151, parameters 152, thresholds 153, and zones 154,stored therein. In other examples, the memory 150 can be configured tostore one or more other type of entry or information, or one or moreother permutations or combinations of these or other entries orinformation. In an example, the input circuit 120 can be configured toreceive physiological information from a patient, such as physiologicalinformation of a heart, or respiratory information. The input circuit120 can be configured to receive information from a variety ofphysiological sensors including electrodes, a heart sound sensor, amicrophone, a pressure sensor, an impedance sensor, a respirationsensor, or one or more other physiological sensors.

In an example, the arrhythmia circuit 110 can be configured to use thereceived physiological information to detect candidate cardiac events.The user interface 130 can be configured to present the candidatecardiac events to a user, such as a clinician, and receive userinformation about the candidate cardiac event from the user. The userinformation about the candidate cardiac event can include whether thecandidate cardiac event should be above or below the threshold, whetherthe candidate cardiac event is a reportable event, or whether thecandidate cardiac event should be displayed to the user. The arrhythmiacircuit 110 can be configured to adjust arrhythmia detection using thereceived user information. Adjusting arrhythmia detection can includeadjusting any one of the boundaries 151, the parameters 152, thethresholds 153, or the zones 154 used for arrhythmia detection.

In an example, the arrhythmia circuit 110 can be configured to use adetection parameter to detect the candidate cardiac event. The detectionparameter can be a parameter from the parameters 152 stored in memory150. The arrhythmia circuit 110 can be configured to adjust either athreshold or the detection parameter using the received userinformation. The threshold can be a threshold from the thresholds 153stored in memory. The arrhythmia circuit 110 can be configured to detecta candidate cardiac event using either the adjusted threshold oradjusted detection parameter. The arrhythmia circuit 110 can beconfigured to adjust the threshold within a predefined safety zone usingthe received user information. The safety zone can be a zone from thezones 154 stored in memory 150. The arrhythmia circuit 110 can beconfigured to detect a candidate cardiac event using the adjustedthreshold that was adjusted within the predefined safety zone.

In an example, the arrhythmia circuit 110 can be configured to detectthe candidate cardiac event within a target zone about a threshold. Thetarget zone can be a zone from the zones 154 stored in memory 150. Thetarget zone can include a lower boundary below the threshold and anupper boundary above the threshold. The upper boundary and the lowerboundary can be from the boundaries 151 stored in memory 150. Thethreshold can be centered between the upper and lower boundary, closerto the lower boundary, or closer to the upper boundary. In an example,the upper boundary can be a predefined amount above the threshold andthe lower boundary a predefined amount below the threshold. In anexample, the upper boundary can be a selectable amount above thethreshold and the lower boundary a selectable amount below thethreshold. In an example, the arrhythmia circuit 110 can be configuredto adjust the upper boundary in response to received user input. In anexample, the arrhythmia circuit 110 can be configured to adjust thelower boundary in response to received user input.

In an example, the received user information can include positivereceived user information, neutral received user information, ornegative received user information. The arrhythmia circuit 110 can beconfigured to adjust a count of a counter from the set of counters 140in response to the received user information. In an example, the countercan be a positive user information counter or a negative informationcounter. In an example, there can be both a positive counter and anegative counter. In an example, the arrhythmia circuit 110 can beconfigured to adjust at least one of the threshold or the detectionparameter when the counter exceeds an update threshold. In an example,the arrhythmia circuit 110 can be configured to adjust a confidenceparameter up in response to positive received user information. Thearrhythmia circuit 110 can be configured to adjust a confidenceparameter down in response to negative received user information.

In certain examples, the system 100 includes an output circuit 160 forproviding a notification to the user or delivering arrhythmia treatmentsto a patient. Notifications can include alerts of arrhythmia detectionadjustment, an alert that the patient needs treatment, or alerts thatuser information is needed in response to a candidate cardiac event. Theoutput circuit 160 can include a speaker for providing audionotifications. The output circuit 160 can include circuitry for sendingan alert to the user interface 130, a computer, a mobile phone, or othermobile computing device capable of receiving notifications.

The output circuit 160 may include circuitry for administeringarrhythmia treatments including administering medication, cardioversion,or defibrillation. In certain examples, the arrhythmia circuit can beconfigured to treat cardiac events that exceed a confidence parameterthreshold.

In certain examples, the system 100 includes a database 170. Thearrhythmia circuit 110 can be configured to retrieve initialization datafrom the database 170. The arrhythmia circuit 110 can be configured toretrieve received user information from the database 170 for adjustingarrhythmia detection. The arrhythmia circuit 110 can be configured torecord candidate cardiac event data and received user information in thedatabase 170. In certain examples, the received user information in thedatabase 170 is used to adjust arrhythmia detection in a population.

In certain examples, the output circuit 160 may include circuitry forcommunicating with the database 170 or a server. The circuitry forcommunicating with the database 170 may include network adapters, suchas a local area network adapters, personal area network adapters, widearea network adapters, or metropolitan area network adapters. The servermay include the database 170 or may communicate with the database 170through a network connection.

FIG. 2 illustrates an example method 200 for detecting cardiac eventsusing physiological information from a patient, such as electrical ormechanical information of a heart, or respiratory information of thepatient, and adjusting the detection of one or more cardiac events basedupon received user information. At 210, an input circuit can receivephysiological information of a patient. The input circuit can include apressure sensor, a heart sound sensor, a set of electrodes, and anexternal programmer. At 212, an arrhythmia circuit can detect acandidate cardiac event. The arrhythmia circuit can use thresholds,zones, boundaries, and parameters as part of arrhythmia detection todetect the candidate cardiac event.

At 214, a user interface can display the candidate cardiac event to auser. The user interface can be a computer, a mobile compute device, anexternal programmer, a monitor, or other display device. At 216, theuser interface can receive user information about the candidate cardiacevent. The user information about the candidate cardiac event caninclude whether the candidate cardiac event should be above or below thethreshold, whether the candidate cardiac event is a reportable event, orwhether the candidate cardiac event should be displayed to the user. Theuser interface 216 can include a set of selectable indicators that theuser can choose from to receive the user information about the candidatecardiac event. The user may be able to indicate a selection using atouch screen, computer mouse, keyboard, or other electronic user input.The received user information can be positive user information, neutraluser information, or negative user information.

At 218, the arrhythmia circuit can adjust arrhythmia detection using thereceived user information. Adjusting arrhythmia detection can includeadjusting at least one of a parameter, a threshold, a boundary, or azone used in arrhythmia detection. In some examples, adjustingarrhythmia detection at 218 includes operations shown at 220 and 222. At220, the arrhythmia circuit can adjust a count of a counter in responseto the received user information. There may be a positive userinformation counter and a negative user information counter. At 222, thearrhythmia circuit can adjust at least one of the threshold or adetection parameter when the count exceeds an update threshold.

FIG. 3 illustrates an example flow chart 300 for adjusting arrhythmiadetection. At 310, an arrhythmia circuit can detect a candidate cardiacevent. At 312, a user interface can present the candidate cardiac eventto a user. The user interface can receive user information about thecandidate cardiac event from the user. The user information about thecandidate cardiac event can include whether the candidate cardiac eventshould be above or below the threshold, whether the candidate cardiacevent is a reportable event, or whether the candidate cardiac eventshould be displayed to the user. In an example, received userinformation can fit into three different categories: neutral or noreceived user information; positive received user information; andnegative received user information.

At 314, the user interface can receive neutral user information, such aswhen a predetermined timeframe for user response elapses for thedetected candidate cardiac event, or when the user selects a selectableindicator to move on to the next candidate cardiac event. At 316, thearrhythmia circuit can maintain a current arrhythmia detection inresponse to the neutral received user information.

At 320, the user interface can receive positive user information. At322, the arrhythmia circuit can increase a confidence parameter inresponse to the positive received user information. At 324, thearrhythmia circuit can update a counter in response to the positivereceived user information. At 326, the arrhythmia circuit can determineif the updated counter exceeds an update threshold. At 318, thearrhythmia circuit can update arrhythmia detection when the updatedcounter exceeds the update threshold. At 316, the arrhythmia circuit canmaintain the current arrhythmia detection when the updated counter doesnot exceed the update threshold.

At 330, the user interface can receive negative user information. At331, the arrhythmia circuit can decrease a confidence parameter inresponse to negative received user information. At 332, the arrhythmiacircuit can update a counter for negative received user information inresponse to the negative received user information. At 334, thearrhythmia circuit can determine if the updated counter exceeds anupdate threshold. At 318, the arrhythmia circuit can update arrhythmiadetection if the updated counter exceeds the update threshold. At 316,the arrhythmia circuit can maintain the current arrhythmia detectionwhen the updated counter does not exceed the update threshold.

FIG. 4 illustrates an example graphical user interface 400 fordisplaying a candidate cardiac event and receiving user informationabout the candidate cardiac event. In an example, the user interface 400includes a date and time 420 of the candidate cardiac event, anarrhythmia type 422 of the candidate cardiac event, an average heartrate 424 during the candidate cardiac event, a duration 426 of thecandidate cardiac event, an electrocardiogram 410 of the candidatecardiac event, and a user response prompt 430 for the candidate cardiacevent.

The user response prompt can include a negative selectable indicator 432and a positive selectable indicator 434. In some examples, the negativeselectable indicator 432 can be a thumbs-down. In other examples, thenegative selectable indicator may be an X symbol, a frowny face, orother negative indicator. In some examples, the positive selectableindicator 434 can be a thumbs-up as shown. In other examples, thepositive selectable indicator may be a checkmark, a smiley face, orother positive indicator. Selection of the negative selectable indicator432 can communicate negative user information or feedback. Selection ofthe positive selectable indicator 434 can communicate positive userinformation or feedback.

FIG. 5 illustrates an example graphical user response prompt 500 forreceiving user information. The accuracy section 510 includes a correctselectable indicator 512 and a wrong selectable indicator 514. Thecorrect selectable indicator 512 can communicate positive userinformation. The wrong selectable indicator 514 can communicate negativeuser information. The clinical value section 520 includes a “Give MeLess” selectable indicator 522 and a “Give Me More” selectable indicator524. Selection of the “Give Me Less” selectable indicator 522 cancommunicate negative user information. Selection of the “Give Me More”selectable indicator 524 can communicate positive user information.

In an example, the graphical user response prompt 500 can be thegraphical user response prompt 430 of FIG. 4. In an example, a userinterface can display all elements shown in the graphical user responseprompt 500. In an example, the user interface can display the selectableindicators of the graphical user interface. In an example, the userinterface may display only the selectable indicators from the accuracysection 510. In an example, the user interface may display only theselectable indicators from the clinical value 520 section.

FIG. 6 illustrates an example cardiac event graph 600 including heartinformation data 630, an x-axis 610, a y-axis 620, first and secondthresholds 611 and 621, safety zones 612 and 622, target zones 615 and625, upper boundaries 616 and 626, and lower boundaries 617 and 627. Theheart information data 630 is taken from a set of physiologicalinformation of a patient. The heart information data 630 shown isrepresented by small dots and plotted on the graph based upon twodifferent parameters, one parameter corresponding to the x-axis 610 andthe other parameter corresponding to the y-axis 620. In an example, thex-axis 610 parameter is a heart rate (HR) scatter ratio and the y-axis620 parameter is a HR double-decrement ratio. In other examples, thex-axis 610 and y-axis can represent other representations of one or moreother physiologic parameters, or combinations of one or more otherphysiologic parameters of interest in arrhythmia detection.

Threshold 611, safety zone 612, lower safety boundary 613, upper safetyboundary 614, target zone 615, lower boundary 616, and upper boundary617 correspond to the x-axis 610 and the data type the x-axis 610represents. The threshold 611 corresponds to the heart data type of the610. The target zone 615 is defined by the lower boundary 616 below thethreshold 611 and the upper boundary 617 above the threshold. Thearrhythmia circuit can detect candidate cardiac events within the targetzone 615. The arrhythmia circuit can adjust the threshold 611, the lowerboundary 616, the upper boundary 617, or any combination thereof inresponse to received user information about the candidate cardiac event.The safety zone 612, defined by the lower safety boundary 613 and theupper safety boundary 614, can represent the area in which adjustmentscan be made. Adjustments of the threshold 611, the lower boundary 616,and the upper boundary 617 can be restricted to within the safety zone612.

Threshold 621, safety zone 622, lower safety boundary 623, upper safetyboundary 624, target zone 625, lower boundary 626, and upper boundary627 correspond to the y-axis 620 and the data type the y-axis 620represents. The threshold 621 corresponds to the heart data type of the620. The target zone 625 is defined by the lower boundary 626 below thethreshold 621 and the upper boundary 627 above the threshold. Thearrhythmia circuit can detect candidate cardiac events within the targetzone 625. The arrhythmia circuit can adjust the threshold 621, the lowerboundary 626, the upper boundary 627, or any combination thereof inresponse to received user information about the candidate cardiac event.The safety zone 622, defined by the lower safety boundary 623 and theupper safety boundary 624, can represent the area in which adjustmentscan be made. Adjustments of the threshold 621, the lower boundary 626,and the upper boundary 627 can be restricted to within the safety zone622.

FIG. 7 illustrates a block diagram of an example machine 700 upon whichany one or more of the techniques (e.g., methodologies) discussed hereinmay perform. Portions of this description may apply to the computingframework of various portions of the LCP device, the 1 MB, or theexternal programmer.

In alternative embodiments, the machine 700 may operate as a standalonedevice or may be connected (e.g., networked) to other machines. In anetworked deployment, the machine 700 may operate in the capacity of aserver machine, a client machine, or both in server-client networkenvironments. In an example, the machine 700 may act as a peer machinein peer-to-peer (P2P) (or other distributed) network environment. Themachine 700 may be a personal computer (PC), a tablet PC, a set-top box(STB), a personal digital assistant (PDA), a mobile telephone, a webappliance, a network router, switch or bridge, or any machine capable ofexecuting instructions (sequential or otherwise) that specify actions tobe taken by that machine. Further, while only a single machine isillustrated, the term “machine” shall also be taken to include anycollection of machines that individually or jointly execute a set (ormultiple sets) of instructions to perform any one or more of themethodologies discussed herein, such as cloud computing, software as aservice (SaaS), other computer cluster configurations.

Examples, as described herein, may include, or may operate by, logic ora number of components, or mechanisms. Circuit sets are a collection ofcircuits implemented in tangible entities that include hardware (e.g.,simple circuits, gates, logic, etc.). Circuit set membership may beflexible over time and underlying hardware variability. Circuit setsinclude members that may, alone or in combination, perform specifiedoperations when operating. In an example, hardware of the circuit setmay be immutably designed to carry out a specific operation (e.g.,hardwired). In an example, the hardware of the circuit set may includevariably connected physical components (e.g., execution units,transistors, simple circuits, etc.) including a computer readable mediumphysically modified (e.g., magnetically, electrically, moveableplacement of invariant massed particles, etc.) to encode instructions ofthe specific operation. In connecting the physical components, theunderlying electrical properties of a hardware constituent are changed,for example, from an insulator to a conductor or vice versa. Theinstructions enable embedded hardware (e.g., the execution units or aloading mechanism) to create members of the circuit set in hardware viathe variable connections to carry out portions of the specific operationwhen in operation. Accordingly, the computer readable medium iscommunicatively coupled to the other components of the circuit setmember when the device is operating. In an example, any of the physicalcomponents may be used in more than one member of more than one circuitset. For example, under operation, execution units may be used in afirst circuit of a first circuit set at one point in time and reused bya second circuit in the first circuit set, or by a third circuit in asecond circuit set at a different time.

Machine (e.g., computer system) 700 may include a hardware processor 702(e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 704 and a static memory 706, some or all of which may communicatewith each other via an interlink (e.g., bus) 708. The machine 700 mayfurther include a display unit 710 (e.g., a raster display, vectordisplay, holographic display, etc.), an alphanumeric input device 712(e.g., a keyboard), and a user interface (UI) navigation device 714(e.g., a mouse). In an example, the display unit 710, input device 712and UI navigation device 714 may be a touch screen display. The machine700 may additionally include a storage device (e.g., drive unit) 716, asignal generation device 718 (e.g., a speaker), a network interfacedevice 720, and one or more sensors 721, such as a global positioningsystem (GPS) sensor, compass, accelerometer, or other sensor. Themachine 700 may include an output controller 728, such as a serial(e.g., universal serial bus (USB), parallel, or other wired or wireless(e.g., infrared (IR), near field communication (NFC), etc.) connectionto communicate or control one or more peripheral devices (e.g., aprinter, card reader, etc.).

The storage device 716 may include a machine readable medium 722 onwhich is stored one or more sets of data structures or instructions 724(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 724 may alsoreside, completely or at least partially, within the main memory 704,within static memory 706, or within the hardware processor 702 duringexecution thereof by the machine 700. In an example, one or anycombination of the hardware processor 702, the main memory 704, thestatic memory 706, or the storage device 716 may constitute machinereadable media.

While the machine readable medium 722 is illustrated as a single medium,the term “machine readable medium” may include a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 724.

The term “machine readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions for execution bythe machine 700 and that cause the machine 700 to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding or carrying data structures used by or associated withsuch instructions. Non-limiting machine readable medium examples mayinclude solid-state memories, and optical and magnetic media. In anexample, a massed machine readable medium comprises a machine readablemedium with a plurality of particles having invariant (e.g., rest) mass.Accordingly, massed machine-readable media are not transitorypropagating signals. Specific examples of massed machine readable mediamay include: non-volatile memory, such as semiconductor memory devices(e.g., Electrically Programmable Read-Only Memory (EPROM), ElectricallyErasable Programmable Read-Only Memory (EEPROM)) and flash memorydevices; magnetic disks, such as internal hard disks and removabledisks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

The instructions 724 may further be transmitted or received over acommunications network 726 using a transmission medium via the networkinterface device 720 utilizing any one of a number of transfer protocols(e.g., frame relay, internet protocol (IP), transmission controlprotocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), Plain Old Telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as WiFi®, IEEE 802.16 family ofstandards known as WiMax®), IEEE 802.15.4 family of standards,peer-to-peer (P2P) networks, among others. In an example, the networkinterface device 720 may include one or more physical jacks (e.g.,Ethernet, coaxial, or phone jacks) or one or more antennas to connect tothe communications network 726. In an example, the network interfacedevice 720 may include a plurality of antennas to wirelessly communicateusing at least one of single-input multiple-output (SIMO),multiple-input multiple-output (MIMO), or multiple-input single-output(MISO) techniques. The term “transmission medium” shall be taken toinclude any intangible medium that is capable of storing, encoding orcarrying instructions for execution by the machine 700, and includesdigital or analog communications signals or other intangible medium tofacilitate communication of such software.

Various embodiments are illustrated in the figures above. One or morefeatures from one or more of these embodiments may be combined to formother embodiments. By way of examples and not limitation, one or morefeatures of the stochastic modulator illustrated in FIG. 9 may beincorporated into other stochastic modulators, and one or more featuresof the user interface illustrated in FIG. 11 may be incorporated intothe systems illustrated in other figures.

Method examples described herein can be machine or computer-implementedat least in part. Some examples may include a computer-readable mediumor machine-readable medium encoded with instructions operable toconfigure an electronic device or system to perform methods as describedin the above examples. An implementation of such methods can includecode, such as microcode, assembly language code, a higher-level languagecode, or the like. Such code can include computer readable instructionsfor performing various methods. The code can form portions of computerprogram products. Further, the code can be tangibly stored on one ormore volatile or non-volatile computer-readable media during executionor at other times.

The above detailed description is intended to be illustrative, and notrestrictive. The scope of the disclosure should, therefore, bedetermined with references to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. A medical device learning system comprising: aninput circuit configured to receive physiological information of apatient; an arrhythmia circuit configured to detect a candidate cardiacevent about a threshold using the received physiological information ofthe patient; and a user interface configured to display the candidatecardiac event to a user, and to receive user information about whetherthe candidate cardiac event should be above or below the threshold,wherein the arrhythmia circuit is configured to adjust an arrhythmiadetection threshold using the received user information that thecandidate cardiac event should be above or below the threshold.
 2. Thesystem of claim 1, wherein the arrhythmia circuit is configured todetect the candidate cardiac event using a detection parameter, andwherein the arrhythmia circuit is configured to adjust at least one ofthe threshold or the detection parameter using the received userinformation that the candidate cardiac event should be above or belowthe threshold.
 3. The system of claim 2, including: a counter, whereinthe arrhythmia circuit is configured to adjust a count of the counter inresponse to the received user information that the candidate cardiacevent should be above or below the threshold, and wherein the arrhythmiacircuit is configured to adjust at least one of the threshold or thedetection parameter when the count exceeds an update threshold.
 4. Thesystem of claim 2, wherein the arrhythmia circuit is configured todetect a cardiac arrhythmia using the adjusted threshold or the adjusteddetection parameter.
 5. The system of claim 1, wherein the arrhythmiacircuit is configured to adjust the threshold within a predefined safetyzone using the received user information.
 6. The system of claim 5,wherein the arrhythmia circuit is configured to detect a cardiacarrhythmia using the adjusted threshold.
 7. The system of claim 1,wherein the received user information about whether the candidatecardiac event should be above or below the threshold includes positivereceived user information, neutral received user information, ornegative received user information.
 8. The system of claim 1, whereinthe arrhythmia circuit is configured to adjust a confidence parameter inresponse to the received user information that the candidate cardiacevent should be above or below the threshold.
 9. The system of claim 1,wherein the arrhythmia circuit is configured to detect the candidatecardiac event within a target zone about the threshold, and wherein thetarget zone includes a lower boundary below the threshold, and an upperboundary above the threshold.
 10. The system of claim 9, wherein thethreshold is centered between the upper boundary and the lower boundary.11. The system of claim 9, wherein the upper boundary is a predefinedamount above the threshold and the lower boundary is a predefined amountbelow the threshold.
 12. The system of claim 9, wherein the upperboundary is a selectable amount above the threshold and the lowerboundary is a selectable amount below the threshold.
 13. A medicaldevice learning method comprising: receiving physiological informationof a patient using an input circuit; detecting, using an arrhythmiacircuit, a candidate cardiac event about a threshold using thephysiological information of the patient; displaying, using a userinterface, the candidate cardiac event to a user; receiving, using theuser interface, user information about whether the candidate cardiacevent should be above or below the threshold; and adjusting, using thearrhythmia circuit, an arrhythmia detection threshold using the receiveduser information that the candidate cardiac event should be above orbelow the threshold.
 14. The method of claim 13, wherein detecting thecandidate cardiac event includes using a detection parameter, andwherein adjusting the arrhythmia detection threshold includes adjustingat least one of the threshold or the detection parameter using thereceived user information that the candidate cardiac event should beabove or below the threshold.
 15. The method of claim 14, includingdetecting, using the arrhythmia circuit, a cardiac arrhythmia using theadjusted threshold or the adjusted detection parameter.
 16. The methodof claim 13, wherein adjusting the arrhythmia detection thresholdincludes adjusting the threshold within a predefined safety zone usingthe received user information that the candidate cardiac event should beabove or below the threshold.
 17. The method of claim 13, including:detecting, using the arrhythmia circuit, the candidate cardiac eventwithin a target zone about the threshold, wherein the target zoneincludes a lower boundary below the threshold, and an upper boundaryabove the threshold.
 18. The method of claim 13, wherein the receiveduser information about whether the candidate cardiac event should beabove or below the threshold includes positive received userinformation, neutral received user information, or negative receiveduser information.
 19. The method of claim 13, including: adjusting acount of a counter, using the arrhythmia circuit, in response to thereceived user information that the candidate cardiac event should beabove or below the threshold; and adjusting, using the arrhythmiacircuit, at least one of the threshold or the detection parameter whenthe count exceeds an update threshold.
 20. The method of claim 13,including adjusting a confidence parameter in response to the receiveduser information that the candidate cardiac event should be above orbelow the threshold using the arrhythmia circuit.